A baseboard management controller (BMC) chip is used for device management on a non-volatile memory express (NVMe) device. A status request instruction is sent to each NVMe device using the BMC chip in order to obtain device management information of each NVMe device. An NVMe technology includes a data plane and a device management plane. As shown in FIG. 1A, a solid line indicates the data plane in which a connection is implemented between central processing unit (CPU) and NVMe devices using a high-speed Peripheral Component Interconnect Express (PCIe) bus, and a dashed line indicates the device management plane in which a connection is implemented using an Inter Integrated Circuit (I2C) bus or a System Management Bus (SMBus). The device management plane focuses on how a device management chip controls, maintains, and monitors an NVMe device card in a system, including but not limited to, in-position detection of the NVMe device, dimension monitoring, hard disk storage space usage, and an error alarm.
The BMC chip regularly sends a command to the NVMe device (for example, sending once every 5 seconds (s)), to query related device management information. After receiving the related command, the managed NVMe device reads all information requested by the query command and returns all the information to a BMC for processing. In most cases, the information returned by the NVMe device to the BMC is unchanged, or is within a normal range. For example, in most cases, temperature information reported by the NVMe device is within a proper range, or is even unchanged, and the BMC does not need to generate an alarm. After receiving same temperature information, the BMC discards the information after performing some determining.
In a small computer system interface (SCSI) architecture, as shown in FIG. 1B, a storage enclosure processor (SEP) chip manages an SCSI device. The SEP chip, such as an MG9071 or MG9072 chip of the American Megatrends, Incorporated (AMI) Company, manages the SCSI device according to device management information fed back by the SCSI device, such as a voltage, a temperature, or a fan. Similarly, in most cases, information returned by the SCSI device to a SEP is unchanged.
Much management bus bandwidth between a BMC and an NVMe device or between a SEP and an SCSI device is occupied because much repeated information is reported during each transmission. Particularly when there are many NVMe devices managed by the BMC or many SCSI devices managed by the SEP, the problem is more serious. Consequently, a quantity of NVMe devices that can be managed by the BMC or a quantity of SCSI devices that can be managed by the SEP are greatly limited.